The present invention relates to a cross shaft joint.
In a power transmitting portion of a vehicle, a cross shaft joint is used to tiltably couple two shaft members to each other. The cross shaft joint includes a cross shaft and four rolling bearings provided in four shaft portions of the cross shaft respectively. The rolling bearing is usually a roller bearing and includes a plurality of needle-shaped rollers and an outer ring cup.
In a conventional cross shaft joint, the outer ring cup is directly fixed to the end of a corresponding shaft member without using a yoke (see Patent Document 1). More specifically, two of the four outer ring cups which are opposed to each other by 180 degrees are integrated in a rotating direction through a key and a key groove at the ends of one of the shaft members, and furthermore, are fixed with a bolt. Two other outer ring cups are also fixed to the ends of the other shaft members in the same way.
Patent Document 1
JP-A-63-303227
In the cross shaft joint described in the Patent Document 1, generally, the schematic shape of the outer ring cup is obtained by die forging in order to enhance the strength of the outer ring cup and to simplify a processing process. In the outer ring cup, an outer ring raceway surface in an inner part is finished with high precision by abrasion after the forging. A side surface and an outer surface such as an outer peripheral surface are left as forged surfaces without finishing. For this reason, a difference in a weight is made for each outer ring cup.
On the manufacturer side of the cross shaft joint, conventionally, the cross shaft joint is assembled into the shaft member. The assembled member of the cross shaft joint and the shaft member is applied to a balancing machine to detect a whole balance. According to a result, a balance piece is attached to the shaft member to carry out a balance adjustment and shipping to customers is then performed.
In the case in which only the cross shaft joint is exchanged in the customer such as a user, however, it is necessary to newly detect and adjust a balance for the whole assembled member including the cross shaft joint. However, the customers usually retain no balancing machine. For this reason, the whole balance adjustment cannot be carried out. Therefore, the customers have to send the assembled member having the cross shaft joint exchanged back to the manufacturer side in order to adjust the balance. Consequently, a great deal of time and labor and an excessive cost are required.